Woodlouse

Woodlouse collage x4

Oniscidea all

Oniscidea woodlouse morphology

Gråsuggor (Isopoda) - Ystad-2020

Dysdera crocata

Woodlouse (Oniscidea) is a crustacean belonging to the order Isopoda, with over 5,000 species identified across various habitats worldwide. Woodlice are characterized by their segmented, oval bodies, which can range in color from grey to brown, and their ability to roll into a ball as a defensive mechanism, a trait specific to the family Armadillidiidae, commonly known as pill bugs or roly-polies. Despite their common name, woodlice are not actually lice and do not parasitize humans or animals.

Description

Woodlice have a rigid, segmented exoskeleton, which they must periodically shed in a process called molting in order to grow. They possess seven pairs of legs and two pairs of antennae, though one pair is often much smaller and less visible. Their size can vary significantly, from a few millimeters to up to 16 millimeters in length, depending on the species.

Habitat and Distribution

Woodlice are found in a wide range of environments, from forests and gardens to caves and deserts, demonstrating their adaptability. They prefer moist environments and are often found under rocks, logs, and leaf litter, where humidity is higher. Woodlice play a crucial role in their ecosystems by breaking down dead plant material, thus contributing to nutrient cycling and soil health.

Behavior and Ecology

Woodlice are primarily nocturnal and are known for their detritivorous diet, feeding on decaying leaf litter and other plant matter. Some species are more selective feeders, consuming fungi or algae. Their behavior of rolling into a ball, exhibited by species in the family Armadillidiidae, serves as a defense mechanism against predators by protecting their softer underparts.

Reproduction

Woodlice reproduce sexually, with some species capable of parthenogenesis, a form of asexual reproduction. Females carry their fertilized eggs in a pouch called a marsupium until they hatch. The young, which resemble miniature adults, remain in the pouch for several days before emerging to fend for themselves.

Conservation

Most woodlice species are not considered threatened and have a wide distribution. However, habitat destruction and pollution can impact local populations. Some species are used as bioindicators to assess the health of their environments.

In Culture

Woodlice have been subjects of curiosity and affection, particularly among children, in various cultures. They are often considered beneficial in gardens for their role in decomposing organic matter.